The background of the invention will be discussed in two parts:
1. Field of the Invention
This invention relates to music synthesizers, and more particularly to a music synthesizer sufficiently small to be held and played by hand and sufficiently inexpensive to be mass produced and made available at a modest cost.
2. Description of the Prior Art
In the past twenty or thirty years, there has been developed a broad line of electronic music instruments which may be generally categorized as music synthesizers. Such devices generate sound entirely by electronic means. The devices create or generate electronic waveforms, which are then shaped and blended together in various manners to create different types of waveforms which can be amplified and played through conventional speakers to create different types of sounds.
One of the more common examples of this type of music synthesizer is the conventional electronic organ. Electronic organs have been developed nad marketed which generate sounds in a variety of electronic manners, such as by using various types of known oscillator circuits to generate waveforms of different frequencies and amplitude, and then passing these waveforms through various types of wave shaping networks to create waveforms corresponding to the desired sounds. Such electronic organs are widely found in private homes and are sometimes used in various types of musical groups and bands. However, they have usually been of such size and bulk that they are, in effect, a piece of furniture which must be located at a fixed location and whose price is relatively high.
Other types of electronic organs have been developed in the prior art which utilize digital computers to generate some of the waveforms which can subsequently be amplified and played through speakers to create various types of conventional or unusual musical effects. Such devices have been substantially smaller than the prior art electronic organs described above, but they still have been sufficiently bulky that they cannot be truly hand held instruments. They require legs or other types of supports. In addition, as is usual in computer type apparatus, the circuits and other peripheral equipment required had been relatively elaborate, requiring developers of such devices to resort to combining digital computer circuits with separate logic and analog circuitry resulting in a substantial manufacturing cost to produce such devices.
In recent years, there has been developed by the semiconductor industry a relatively simple, inexpensive device known as a microprocessor. A microprocessor is a small programmable digital computer which is formed on a single semiconductor chip. Such devices typically include a first section which is a true small digital computer, having the various calculating circuits, registers and other components found in conventional digital computers, and a second section which may be termed a read only memory (ROM). In the manufacture of the microprocessor, the program is, in effect, "written" into the ROM by providing suitable masks to create the necessary microcircuitry therein. The program which controls the digital computer is thus permanently written into the computer. The digital computer is then said to be "dedicated" to the particular task for which the program is written into the ROM.
Such microprocesses are physically small and light weight, thereby facilitating their use in small, hand-held devices. In addition, if the microprocessor is produced in sufficient volume to amortize the cost of the design of the program and the masks of the ROM over a large number of microprocessors, they are relatively inexpensive and can be used in devices having modest selling prices.
It is accordingly an object of the present invention to provide a new and improved music synthesizer;
It is another object of the present invention to provide a new and improved music synthesizer which is sufficiently small and light weight to be held by hand and which is sufficiently inexpensive to be made available on a mass market;
It is yet another object of the present invention to provide a new and improved computer geometry to enable a music synthesizer to be built utilizing a single microprocessor as the digital computer means for performing all the control, sequencing, and waveform generation functions necessary to implement a music synthesizer.